Please make sure that you follow below steps:
1/ Download the package from themeforest.net (the file is in zip format)
2/ Extract the file you've just downloaded.
3/ Find this file: ella-3.0.0-sections-ready.zip in the folder Ella Sections Ready 3.0.0, then you just need to upload ella-3.0.0-sections-ready.zip file to your Shopify store.
To save your time and reach our support quickly, please follow below steps:
1/ Create a staff account for us (with Themes permission and Settings permission) http://docs.shopify.com/manual/settings/account/staff-members
2/ Capture screenshot or video for the issue you get.
3/ Specify which template and version you are using.
4/ Describe clearly how to reproduce the issue.
5/ Send all information (staff account, screenshot, video, template name and version, description of the issues, link) to firstname.lastname@example.org